JPH0569361A - Device for exchanging robot tool and preventing overload - Google Patents

Abstract

PURPOSE: To provide a robot device having a tool exchanging function and a release function based on overload. CONSTITUTION: A robot tool exchanging and overload prevention device has separable plates 32, 34 connected respectively to a robot arm and to one end of a tool. A magnet 38 is connected to one of the plates and a steel insert is connected to the other of the plates to generate a magnetic attraction force between the magnet and the insert. A pair of conical bearing surfaces 44, 46 are formed at an angle and a depth such that they interconnect the plates during the period of normal operation and produce pivotal release movement between the plates when an overload force is applied to the plates. A flange 20 provided on one of the plates is removably stored within a tool placing table. Means 58-70 are provided for supplying a pneumatic release force between the plates to allow separation between the plates 32, 34 along a Z axis without imposing an overload force on the robot arm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overload preventing device for releasing one end of an arm tooling (device) from a robot arm in order to prevent overloading to a robot arm, and more particularly to a tool (tooling) storage. The present invention relates to an overload prevention device having a robot tool exchange plate that is detachably accommodated in a unit.

[0002]

Robotic tool changers are known, a first plate adapted to be connected to a robot arm and a second plate adapted to be connected to one end of an arm tool (tool) for a robot. Have and. In such a configuration,
A coupling device is provided between the first plate and the second plate to align the plates and bond the plates together so that the robot may be connected between the first plate and the second plate during operation of the robot. Secure the arm tool to the robot arm to provide a strong joint. An example of such a tool changer is disclosed in U.S. Pat. No. 4,793,053.

In this US patent, a pair of deep draft frustoconical annular surfaces are provided between a first plate and a second plate to provide a strong non-rotating joint between the plates. .. The frusto-conical surface has a depth and support surface that prevents separation of the first and second plates other than along the Z or longitudinal axis of the joined plates.

Another device is provided between the robot arm and the arm tooling device to prevent overload forces from being applied to the robot arm during robot operation. Such a device is disclosed in U.S. Pat. No. 14,860,864.

In this US patent, a magnet and a steel plate are connected to the device between a first plate and a second plate, and a magnetic attraction force is maintained between these plates to connect the robot arm and one end of the arm tooling device. Complete the joint between. One plate is provided with a cam surface, and the other plate is provided with a tapered recess shape so that one of the plates is loaded when the load acting on the end of the arm tooling device exceeds the overload condition on the robot arm. When the plate is twisted along at least one of the three-dimensional coordinate axes, the magnet is separated from the steel plate (insert) on the other plate.

[0006]

The above-mentioned US Pat. No. 4,7
The robot tool changer of 93,053 and the separable coupling mechanism of U.S. Pat. No. 4,860,864 are suitable for their own intended use, but these tool changers and The separable linkage cannot perform any other function.

An object of the present invention is to have a pair of separable plates located between the robot and the arm tooling device,
It is to provide a single device having both a tool changing function and an overload releasing function.

[0008]

In order to achieve the above-mentioned objects, the features of the robot tool exchanging and overloading device of the present invention are the first plate and the second plate.
Relative between the first plate and the second plate when a moment provided on the plate and strong enough to overcome the magnetic force between the first plate and the second plate is applied between the first plate and the second plate. Depth and tilt angle at an acute angle to the longitudinal axis through the first and second plates to define a pivot point for producing the pivotal separation and to allow relative pivotal separation Interengaging slanted surfaces having; first for producing a separation between the first and second plates independent of application of any overload moment to the first and second plates; Release means for applying a release force between the plate and the second plate to cause movement of the first plate with respect to the second plate in the direction of the longitudinal axis.

Overload moments on the first and second plates to allow separation movement of the first plate from the second plate within the Z-axis when the arm tooling device is retained in the tool store. Pneumatic release means may be provided which are operative to cause separation of the first and second plates independent of application of the.

The inclined surface is preferably a frusto-conical surface. The releasing means is capable of releasing the first plate and the second plate in the Z axis without applying an excessive load to the robot arm when the arm tooling device is supported by the tool storage unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A robot 10 shown schematically in FIGS. 1 and 2 comprises a robot arm 12 having an end plate 14 connected to one end of a robot tool changing and overloading device 15 according to the present invention.
Have.

The other end of the robot tool exchanging and overload preventing device 15 is connected to a plate 16 provided at an end of an arm tooling device (EOAT) 18 whose external view is schematically shown. According to one principle of the invention, the robot tool change and overload protection device 15 includes a tool storage 24.
A mounting flange 20 for detachably supporting the device 15 is provided in the supporting recess 22 of the. The tool storage unit 24 is
Although shown as having a single support recess, it should be appreciated that it actually has multiple support recesses. Each support recess 22 has substantially the same depth as the height of the mounting flange 20, and the robot tool change and overload prevention device 1
5 is formed by a pair of spaced rails 26, 28 that form a support track for capturing the mounting flange 20 to prevent movement of the mounting flange 20 along the Z-axis. The mounting flange 20 includes a side opening 3 for removing the selected arm tooling device from the tool storage 24.
It is possible to move in the transverse direction of the tool storage section 24 through 0. A specific arm tooling device is selected according to a processing procedure (sequence) to be performed on the workpiece by the robot 10.
According to one principle of the invention, the robot tool change and overload protection device 15 has an upper plate 32 and a lower plate 34. As shown in FIGS. 3 and 4, the upper plate 32 has a circular opening 35 in which a support plate 36 is attached. The support plate 36 is oriented with respect to the air supply and electrical connections (discussed below) by a dowel pin 37 fitted between the plates 32 and 34. The upper plate 32 also carries a rectangular permanent magnet 38 at the end flange 38a. Permanent magnet 38 is connected to the inner surface of the upper plate by suitable stop means.
The permanent magnet 38 may be a type of MAGNEQUENCH magnetic cell (trade name) manufactured by General Motor Company of the United States. For a more detailed description of such permanent magnets, see US Pat. No. 4,496,395.

The permanent magnet 38 is operatively associated with a steel insert 42 which is threaded onto an inner threaded insert 45 of the lower plate 34 to attach to the inner surface 34a of the lower plate 34. Connected.

When the permanent magnet 38 is positioned with respect to the steel insert 42 at a predetermined distance, the magnetic attraction force for connecting the upper plate 32 and the lower plate 34 is applied to these plates 32, 34.
It occurs in the meantime. In particular, the upper plate 32 has a frustoconical surface 44 that defines a recess that accommodates a corresponding frustoconical surface 46 of the lower plate 34. Upper plate 32 and lower plate 3
When 4 and 4 are magnetically coupled to each other, frustoconical surfaces 44, 46 lie in overlapping relationship with each other, as shown in FIG. The frusto-conical surfaces 44, 46 define support surfaces for supporting normal loads on the robot arm 12 and arm tooling device 18.

According to one principle of the present invention, the frustoconical surfaces 44, 46, as shown in FIG. 5, when an overload force is exerted between the upper plate 32 and the lower plate 34,
One side of the bottom plate 34 has a depth D such that it is tiltable downwards with respect to the other side of the plate 34. Frustoconical surface 4
As shown in FIG. 6, the reference numerals 4, 46 have an inclination angle 48 forming an acute angle with respect to the direction of the Z axis 50 of the robot tool changing and overload preventing device 15. Frustoconical surface 4
The inclination angle 48 and the depth D of 4, 46 cooperate to generate an overload releasing moment 52 due to a force acting on the robot tool change and overload prevention device 15 in the Z axis direction along the X direction or the Y direction. Guarantees complete separation of these plates when they work.

As shown, such an overload release moment 52 causes a pivotal movement between the combined normal operating position of FIG. 5 and the inclined disengaged position of FIG. In order to move to the inclined separating position, the overload releasing moment 52 causes the relative separating force exceeding the magnetic attractive force between the permanent magnet 38 and the steel insert 42 between the upper plate 32 and the lower plate 34. Must be generated. When this relative separating force is generated, the lower plate 34 separates as shown in FIG. 6 at an arbitrary point on the circumference of the robot tool exchange and overload prevention device 15, and at this point, the upper and lower plates 32, 34 are separated from each other. Is substantially eliminated, the overload force is not transmitted to the robot arm 12, and the robot 10 is not damaged. Upper and lower plates 32, 34
Can be completely separated. Alternatively, the upper and lower plates can be tethered so that the arm tooling device 18 remains loosely connected to the separated robot arm 12.

In the illustrated arrangement, frustoconical surfaces 44, 46 are formed around the entire circumference of respective upper and lower plates 32, 34. With the structure formed on the entire circumference, the upper plate 32 and the lower plate 34 are freely released in any direction, and the robot arm 12 acts on the arm tooling device 18 during the operation period of the robot 10. Prevent overloading of robots that you don't want in any direction.

According to another principle of the invention, the support plate 36 on the upper plate 32 has a surface 54 arranged perpendicular to the Z axis 50. The lower plate 34 is perpendicular to the Z axis, and the upper and lower plates 32, 34 are
Has a surface 56 adjacent and opposite the surface 54 when joined.

As shown in FIG. 5, an upper plate 32 and a lower plate 34
When and are interlocked, the opposing surfaces 54, 56 are positioned in sealing engagement with each other. Surface 56 has an annular channel 58 covered by an annular segment 60 of surface 54. High pressure air is introduced into the annular channel 58 through the threaded inlet 62 of the upper plate 32 and then through the axial passage 64 of the support plate 36.

The threaded inlet 62 is connected to an air supply pipe 66 for introducing air from a pressure source 70 of the robot 10 and having a control valve 68 for selectively opening and closing this pipe. .. The pressure source 70 also supplies air pressure to the arm tooling device 18. Such pneumatic supply to the arm tooling is provided through the threaded openings 72 in the upper plate 32 and then the drill holes 74, 76, 78, 80.
Done through. The drill holes 78 are sealed by O-rings 82 and 84 at the upper and lower ends of the support plate 36. The drill holes 80 connect to air ports 86, 86 '(only port 86 is shown in FIG. 5) that supplies pressurized air to the arm tooling device 18. The air supply path to air port 86 '(FIG. 2) is similar to that described above. Similar elements shown in FIG. 2 are given the same reference numbers, followed by a dash (').
Is attached.

The airflow through the control valve 68 is placed under the control of a robot controller 88, which controls valve 10 when it is desired to disconnect or connect the robot 10 to the arm tooling device 18 in the tool store 24. Simultaneously with opening 68, the robot driver 90 is operated so as to move the robot arm 12 in the Z direction of the robot tool change and overload prevention device 15.

As shown in FIG. 4, the power from the electrical power source 91 for the arm tooling device 18 is a set of pin contacts (each set comprises four pin contacts) 9
2, 94 are supplied. The pin contact set 92 has female pins and is held in the upper plate 32 by a set screw 96. The pin contact set 94 has male pins held in place on the lower plate 34 by setscrews 98. The terminals 100 and 102 on the pin contact sets 92 and 94 are adapted to be connected to the electric power source 91 and the arm tooling device 18, respectively. Power supply to the arm tooling device 18 is controlled by the robot controller 88.

More specifically, the operation of releasing the arm tooling device 18 from the robot 10 by the above-described robot controller is as follows. The robot tool change and overload protection device 15 is moved transversely through the side openings 30 to be retained within selected support recesses 22 of the tool reservoir 24 having multiple support recesses. At this point, in order to perform the tool changer release operation in accordance with the present invention, the robot controller 88 opens the control valve 68 and simultaneously drives the robot to cause movement of the robot arm 12 in the Z-axis direction only. The child 90 is activated.
When the robot arm 12 moves vertically, the annular channel 5
Pressure is introduced at 8. This air pressure acts on the annular segment 60 of the surface 54 to generate a release force between the upper plate 32 and the lower plate 34 that is large enough to overcome the magnetic attraction between the permanent magnet 38 and the steel insert 42. .. Therefore,
The robot arm 12 is separated in the tool store 24 from the arm tooling device 18 supported by the mounting flange 20. This separation is performed by the robot arm 12 and the robot 1.
0 without overloading and without damaging them.

The connection for the tool exchange of the robot arm 12 to the arm tooling device 18 is achieved by performing an operation opposite to the above-mentioned releasing operation. In detail,
The upper plate 32 is moved along the Z axis until the permanent magnets 38 are attracted from the tool store 24 to the steel insert 42 of the lower plate 34 of the arm tooling device 18 to be selected. The control valve 68 is closed so that no air release force acts between the adjacent surfaces 54,56. Once the upper plate 32 and the lower plate 34 are joined, the robot tool change and overload protection device 15 is moved transversely through the side opening 30 to remove the arm tooling device 18 from the tool storage 24, and the arm tooling device 24 To prepare for the desired robot control processing procedure.

[Brief description of drawings]

FIG. 1 is an elevational view of a robot tool change and overload prevention device of the present invention shown in cross section held in a tool storage.

2 is a cross-sectional view of the robot tool changing and overload preventing device of the present invention taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

4 is a sectional view taken along line 4-4 of FIG.

5 is a cross-sectional view taken along line 5-5 of FIG.

FIG. 6 is a sectional view similar to FIG. 3, but showing the condition in a tilted separation position.

[Explanation of symbols]

 10 Robot 15 Robot Tool Change and Overload Prevention Device 18 Arm Tooling Device 32 First Plate 34 Second Plate 38 Magnet Means 44, 46 Inclined Surface 48 Inclined Angle 50 Longitudinal Axis 54, 56 Opposing Surface 58 Annular Channel 60 Annular Segment 62 Threaded inlet 64 Axial passage 66 Air supply pipe 68 Control valve 70 Pressure source

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Zyon Kovack, Alice, Utika, Michigan, 48087, 13649 (72) Inventor, Dante Cataldo Zutcalo, Michigan, USA, 48002, Tabspring, 15705 (72) Invention Frank Frank Joseph Kudowa Michigan, USA 48473, Swarts Creek, West Roundhouse 4298, Apartment No. 8

Claims (5)

[Claims] 1. A first plate (32) connectable to a robot.
A robot having a second plate (34) connectable to one end of the arm tooling device (18) and a magnet means (38) for generating a magnetic force to hold the first plate and the second plate together. In the tool exchange and overload prevention device, a moment provided to the first plate and the second plate and having a magnitude that overcomes the magnetic force between the first plate and the second plate is the same as that of the first plate and the second plate. The first plate and the second plate when added between the plates
Through the depth (D) and the first plate and the second plate that define a pivot point for producing relative pivotal separation with the plate and allow the relative pivotal separation. Longitudinal axis (5
0) and mutually engaging sloping surfaces (44, 46) having an acute sloping angle (48); first plate and second;
A releasing force is applied between the first plate and the second plate so as to cause the separation between the first plate and the second plate independently of applying an arbitrary overload moment to the plate. And a releasing means (58-70) for causing movement of the first plate with respect to the second plate in the direction of the longitudinal axis. 2. A first circular sloping surface that defines a female recess formed on the first plate (32) in a circumferential direction of the magnet means in a relationship surrounding the magnet means. (44); and a second circular inclined surface (46) formed on the second plate (34), wherein the first circular inclined surface and the second circular inclined surface form the first plate and the second plate. And a second circular beveled surface defining a male insert positionable within the female recess for coupling together and. 3. The releasing means comprises opposed surfaces (54, 54) formed on the first plate (32) and the second plate (34).
56) and means (58-7) for directing a pressure medium between the opposing surfaces to overcome the attractive force of the magnet means (38).
0) and the robot tool change and overload prevention device according to claim 1 or 2. 4. Means for guiding said pressure medium is provided in said first plate (32) therethrough and comprises a source of pressurized air (6).
6-70) to connect to the air passage (62,
64) and; provided in the second plate (34) and communicating with the same air passage when the first plate and the second plate are held together by the magnet means (38). Annular channels (58, 6) facing each other and sealed to the first plate
0) and; are included, The robot tool changing and overload preventing device according to claim 3. 5. The source of pressurized air comprises a pressure source (70),
The robot tool change and overload prevention device according to claim 4, further comprising a control valve (68) for controlling pressurization of the releasing means.